Spray nozzles are used in many industrial, agricultural, and commercial applications in which it frequently is necessary to remove the spray tip for various reasons, such as inspection and cleaning, replacement of a worn spray tip or seals, or substitution of the spray tip in order to change the spray pattern. It is desirable, therefore, that such spray nozzle assemblies permit quick and easy spray tip removal, while insuring precise tip orientation and reliable sealing characteristics upon replacement.
Most standard spray nozzles use a threaded pipe connection for attachment to the fluid source. There are significant limitations to the utility of such spray nozzles in many applications. If it is necessary to orient the discharging spray pattern in a specific direction, the spray nozzle must be manually realigned each time the nozzle is removed and replaced. Tools also usually must be used when installing or removing threaded spray nozzles, which is time consuming and expensive.
Various quick disconnect spray nozzle assemblies have been proposed in order to enable the spray tip to be installed and removed by hand. Some quick disconnect nozzle assemblies have utilized an O-ring sealing member and a pressure applying spring which biases and maintains the spray tip in its operative and sealed position. Some quick disconnect spray nozzle assemblies have used an elongated, tubular-shaped combination seal and pressure exerting member, which eliminates the need for a separate biasing spring. Such quick disconnect spray nozzles can require the user to exert a significant manual force on the spray tip in order to overcome the force of the spring or elongated sealing member during assembly of the spray tip in the nozzle body. In some cases, the spray nozzle tip can be inserted in the nozzle body and twisted beyond its mounted position, necessitating that the spray tip be twisted repeatedly in opposite directions to insure proper alignment. Moreover, since the elongated combination sealing and biasing member used in quick disconnect nozzles of the foregoing type are mounted internally within the nozzle body, it also is difficult to observe whether the seal is in properly installed condition.
Furthermore, since it is common practice to flush and clean spray nozzles with the spray tips removed, this can cause the sealing member disposed within the nozzle body to become dislodged and forcefully ejected from the body by pressurized cleaning liquid directly through the nozzle, necessitating retrieval and replacement. On the other hand, proposals for mounting large tubular sealing and biasing members on the tip have not been considered desirable because it would significantly increase the size and mass of each spray tip.
Other quick disconnect spray nozzle assemblies utilize camming surfaces adapted for moving the spray tip into and out of biased engagement with a sealing member as an incident to rotation of the spray tip. These spray nozzle assemblies typically use O-rings or smaller sized annular sealing members. Such O-ring seals are more susceptible to leakage, particularly at low pressure start-up conditions, and may lose strength sufficient to adequately maintain the spray tip in operative or properly aligned position. Typically, a plurality of such O-rings are required to achieve proper sealing and biasing, which results in additional components that must be handled and replaced, and which can be lost or misplaced.
To make the spray nozzle body and quick disconnect tips with the necessary intricate camming and locking surfaces for reliable operation, it has been common to plastic injection mold such components. Plastic spray nozzle assemblies, however, may be unsuitable for long term reliable usage in many industrial and commercial applications. Heretofore it has been difficult to efficiently or economically machine intricate camming and locking elements in metal quick disconnect nozzle bodies and tips.